I wouldn't say "mostly"... Mostly, I seemed to find pallete swaps of existing clothing that had extreme stats, and people playing around trying to make personal homes or dungeons of quality levels underlining Sturgeon's Law.
The sex spells were just really popular for obvious reasons.
They had plenty of funny stuff, too, like the one where they made a pink unicorn with rainbows on it that looked like a My Little Pony, and tried to make it fart butterflies, while the character riding it was a demon wearing armor like Lord Sauron.
Anyway, I liked some of the better housing mods, like the one where it was an alternate dimension consisting of a small set of ruins levitating in an empty cloudy sky, and I made some custom companions, and dressed one up as a witch, and had another as a demoness in red platemail, while I went with the blue battlemage armor set and wore glasses and used a book as a weapon. (Everyone was a mage/rogue, basically, it kept them from running in front of me to cause friendly fire, plus I gave them summon spells to be cannon fodder.)
Then I went around the world looking for more Bog Beacon Asco Cap because I found things like alchemy and playing Pretty Princess Dressup and trying to rearrange the silverware on my table or the books in my bookshelf more entertaining than the game itself.
Oh, and they did things like Crafty Bits, too. And damage locations and such... OBSE had alot of cool things, although it did bring in the sex stuff, too.
(And there were all the Japanese mods that had Touhou characters in it, too...)